Database Names

ArangoDB will always start up with a default database, named _system.
Users can create additional databases in ArangoDB, provided the database
names conform to the following constraints:

Database names must only consist of the letters a to z (both lower and
upper case allowed), the numbers 0 to 9, and the underscore (_) or
dash (-) symbols
This also means that any non-ASCII database names are not allowed

Database names must always start with a letter. Database names starting
with an underscore are considered to be system databases, and users should
not create or delete those